That's what caught me off guard. I was told I was not allowed to do side mount for my NAUI Cave 1 class and so I did it backmount. Later, I was shadowing a NAUI Cave 1 class and had to dive backmount. I mentioned this to a NAUI rep at a dive shop one day, intimating that the instructors needed to lighten up. WHOA. He was blistering in his condemnation of sidemount and how it would NEVER be a part of NAUI's curriculum. What if he's right?
That's a shame. Glad I'm not a NAUI instructor. I teach cave and tech through 5 different agencies and they all allow me to teach in sidemount.